1. Field of the Invention
The present invention relates to a vehicle disk brake. More particularly, the present invention relates to a vehicle disk brake provided with a manual release unit capable of manually releasing contact between a disk and a friction pad, which are locked in a braking state of the vehicle.
2. Description of the Prior Art
In general, a vehicle disk brake produces braking force by partially pressing a disk from both sides of the disk that rotates together with a wheel, by using friction pads. Such a vehicle disk brake comprises a disk rotating together with a wheel of the vehicle, friction pads that generate braking force through contact with one side of the disk, a wedge member provided at one side thereof with the friction pads and moved toward the disk by a driving motor that generates force, and a guide member that guides the wedge member toward the disk. Thus, the wedge member is sandwiched between the disk and the guide member due to frictional force generated between the friction pads and the disk, so that great braking force can be obtained.
The conventional disk brake further comprises a power transmission member capable of moving the wedge member toward the disk being rotated while rotating by the driving motor. In order to move the power transmission member toward the disk being rotated, a male screw is formed in a rotating shaft of the driving motor and a shaft hole having a female screw is formed through the power transmission member, so that the power transmission member can move toward the disk according to a rotation direction of the rotating shaft.
Further, in order to perform a braking operation, the disk brake employs a booster that reduces speed of the disk by using rotational force of the driving motor, and reduces displacement of the disk brake to perform a boosting operation. The disk brake may use a pair of wedge members, which have inclination surfaces corresponding to each other, as the booster. As the wedge members move reciprocate, the friction pads make contact with the disk or the friction pads are spaced apart from the disk, so that the braking operation can be performed.
However, in the conventional vehicle disk brake, if the disk and the friction pads are locked while making contact with each other due to malfunction of a motor or power failure, the contact between the disk and the friction pads may not be released.